"missing" RNA

Karen Ferri (kferri at email.unc.edu) wrote:
<snip>
: Homogenized some tissue, isolated and purified the RNA, checked OD's, and
: ran on a gel to check RNA integrity. For 1 sample, the gel lane was
: blank (not even smeared, which would indicate denaturation). I ran 3
: gels to be sure the problem of possible RNA omission to gel lane was
: addressed. Still no run, even after adding extra RNA to lane. The [] of
: the sample (I checked it twice) was 17% lower the second time, but acc.
: to my boss, still not low enough to not show up.
<snip>
Karen,
I think there's no RNA in this particular sample (or very few). I guess
you determined the [RNA] spectorphotometrically. Did you get a 260/280nm
ratio of about 1,7? Even if you did - getting a visible pellet and having
absorption at 260nm doesn't necessarily mean that this is RNA. As far as
I know at least the pellet may well consist of carbohydrates.
If I don't see anything on the gel I asume that there is no RNA in it.
Cheers
Klaus
--
Klaus Salger phone : ++49 (0)89 5902 -502
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